MOSFET Electroscope (CB1392E )

 
   This circuit is from a 1976 documentation. It makes use of isolated gate MOSFET which is already very difficult to obtain. The circuit can be adapted to use a JFET. The indicating instrument may be the lowest range of currents on a multimeter. The power can be made by common battery. The sensor is a metal sphere approximately 1 cm in diameter.

 


Circuit Bench